kernel_optimize_test/init
Randy Dunlap bfe8df3d31 slow down printk during boot
Optionally add a boot delay after each kernel printk() call, crudely
measured in milliseconds, with a maximum delay of 10 seconds per printk.

Enable CONFIG_BOOT_PRINTK_DELAY=y and then add (e.g.):
"lpj=loops_per_jiffy boot_delay=100"
to the kernel command line.

It has been useful in cases like "during boot, my machine just reboots or the
screen goes black" by slowing down printk, (and adding initcall_debug), we can
usually see the last thing that happened before the lights went out which is
usually a valuable clue.

[akpm@linux-foundation.org: not all architectures implement CONFIG_HZ]
[akpm@linux-foundation.org: fix lots of stuff]
[bunk@stusta.de: kernel/printk.c: make 2 variables static]
[heiko.carstens@de.ibm.com: fix slow down printk on boot compile error]
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:49 -07:00
..
calibrate.c slow down printk during boot 2007-10-16 09:42:49 -07:00
do_mounts_initrd.c Fix failure to resume from initrds 2007-09-19 11:24:17 -07:00
do_mounts_md.c [PATCH] md: remove MAX_MD_DEVS which is an arbitrary limit 2006-10-03 08:04:18 -07:00
do_mounts_rd.c [PATCH] devfs: Remove devfs from the init code 2006-06-26 12:25:05 -07:00
do_mounts.c init: wait for asynchronously scanned block devices 2007-07-16 09:05:45 -07:00
do_mounts.h Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
initramfs.c initramfs: missing __init 2007-07-26 11:11:56 -07:00
Kconfig sched: group scheduler, fix coding style issues 2007-10-15 17:00:12 +02:00
main.c fix maxcpus=1 oops in show_stat() 2007-08-30 21:54:31 -07:00
Makefile [PATCH] disable init/initramfs.c 2007-02-11 10:51:25 -08:00
noinitramfs.c [PATCH] disable init/initramfs.c 2007-02-11 10:51:25 -08:00
version.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00